Primocerus cuspidis, Girón & Short, 2019

Giron, Jennifer C. & Short, Andrew Edward Z., 2019, Three additional new genera of acidocerine water scavenger beetles from the Guiana and Brazilian Shield regions of South America (Coleoptera, Hydrophilidae, Acidocerinae), ZooKeys 855, pp. 109-154 : 140

Primocerus cuspidis sp. nov. Figs 11 A–D , 14L , 15B , 16A

Type material.

Holotype (♂): "VENEZUELA: Amazonas/ 5°23.207'N, 67°36.922'W; 125 m/ Tobogán de la Selva, old “Tobogancito” / on seepage area with detritus/ 8.viii.2008; leg. A. Short, M. García, / L. Joly; AS-08-080b" (MIZA). Paratypes (3): VENEZUELA: Amazonas: same data das holotype (SEMC, 3).

Differential diagnosis.

Primocerus cuspidis belongs to the group of species with shallowly impressed, rather irregularly distributed, and undifferentiated elytral punctures. It can be easily distinguished among its congeners by its paler (orange) coloration, and the presence of a sharp, pyramidal (triangular) projection on the posterior elevation of the mesoventrite.

Description.

Body length 2.4 mm, width 1.5 mm. Body elongate oval, moderately convex (Fig. 11B ). General coloration orange-brown. Elytra with ground punctures shallowly marked; serial punctures absent. Posterior elevation of mesoventrite with sharply pointed pyramidal (triangular) spine. Metafemora with hydrofuge pubescence covering basal 4/5. Apex of fifth abdominal ventrite slightly emarginate. Aedeagus (Fig. 14L ) with basal piece 1.3 × longer than parameres; parameres 1.15 × longer than median lobe; distal end of parameres with anteapical constriction, apex rounded and obliquely directed; apex of median lobe widely rounded.

Etymology.

Named with the Latin word cuspidis meaning point, in reference to the sharp projection on the posterior elevation of the mesoventrite.

Distribution.

Primocerus cuspidis has only been collected at Tobogán de la Selva in the Venezuelan Amazon, at an elevation of 125 m (Fig. 15B ).

Remarks.

The type series was collected in a flat, horizontal seepage area that was formed from water seeping from the banks of the Rio Coromoto (Fig. 16A ).

Figures

Figure 11. Habitus of Primocerus spp.: A-D Primocerus cuspidis: A dorsal view B lateral view C ventral view D head, dorsal view. E-H Primocerus neutrum: E dorsal view F lateral view G ventral view H head, dorsal view. Scale bars: 1 mm.

Figure 14. Thorax, abdomen and aedeagus of Primocerus spp.: A-D Primocerus neutrum: A ventral view of mesoventrite (white arrow pointing transverse ridge) B posterior view of metafurca C fifth abdominal ventrite D aedeagus. E-L aedeagus: E, F Primocerus maipure: E dorsal view F lateral view. G, H Primocerus pijiguaense: G dorsal view H lateral view I Primocerus gigas J Primocerus petilus K Primocerus striatolatus L Primocerus cuspidis. Scale bars: 0.25 mm.

Figure 15. Distribution of Primocerus spp.

Figure 16. Habitat of Primocerus spp. A habitat and type locality for P. cuspidis, Venezuela, Tobogan de la Selva, collecting event AS- 08 - 080 b B habitat and type locality for P. pijiguaense, Venezuela, Los Pijiguaos, collecting event AS- 07 - 015 C habitat and type locality for P. neutrum, Venezuela, along La Escalera, collecting event AS- 08 - 058 D habitat and type locality for P. petilus, Brazil, Vale do Paraiso, collecting event BR 18 - 0203 - 01 G.